April Kravchenko had cancer, prescriptions for opioids and a son with an OxyContin problem. Trying to keep Zachary Ross from getting his hands on his mother’s medications when she was hospitalized, Kravchenko’s sister called Sheeley’s Drug Store, in Scranton, Pennsylvania, and asked the pharmacy to block Ross from picking up refills. But Ross allegedly conned a pharmacist into handing over fentanyl patches — even though the receipt said: “Do Not Give To Son.”Ross’s friend Cody …